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SYSCALL(2) | System Calls Manual | SYSCALL(2) |
NAME¶
syscall
,
__syscall
—
indirect system call
LIBRARY¶
Standard C Library (libc, -lc)SYNOPSIS¶
#include
<sys/syscall.h>
#include
<unistd.h>
int
syscall
(int
number,
...);
off_t
__syscall
(quad_t
number,
...);
DESCRIPTION¶
Thesyscall
() function performs the system
call whose assembly language interface has the specified
number with the specified arguments. Symbolic
constants for system calls can be found in the header file
<sys/syscall.h>
.
The __syscall
() form should be used when
one or more of the arguments is a 64-bit argument to ensure that argument
alignment is correct. This system call is useful for testing new system calls
that do not have entries in the C library.
RETURN VALUES¶
The return values are defined by the system call being invoked. In general, a 0 return value indicates success. A -1 return value indicates an error, and an error code is stored in errno.HISTORY¶
Thesyscall
() function appeared in
4.0BSD.
BUGS¶
There is no way to simulate system calls that have multiple return values such as pipe(2).June 16, 1993 | Debian |